Yes. For example, religion and some other metaphysical stances involve belief, but they are not pseudoscience, so long as they don't claim to be science.
The defining characteristic of pseudoscience, surely, is an idea or system of ideas that claims to be science while lacking one or more of science's core elements. To put these at their simplest, the would be the creation of models of the physical world that are testable by means of objective observation of it.
Pseudoscience may involve ideas that do not relate to the physical world, or ideas that cannot even in principle ever be tested, or subjective evidence and uncorroborated anecdote. But the key is that it has these inadmissible features while purporting to be science.
Intelligent design is perhaps the classic example. Alchemy, astrology, kinesiology, reflexology all also qualify.
I also take Yazata's point that most scientists do "believe" in their models to some degree. Strictly, we should treat them all with a degree of circumspection, in view of their provisional nature. The reality is that there are some we place so much confidence in that we effectively "believe" in them. But believing in them is as far as we can go, as we know they can never have the status of a proven fact.
